In a case where passengers get into and off an aircraft (airplane) in an aircraft, a passenger boarding bridge coupling a terminal building to the aircraft is sometimes used.
The passenger boarding bridge includes a rotunda connected to a platform of the terminal building, a tunnel section having a base end connected to the rotunda and being extendable and retractable, and a cab (head) provided at the tip end of the tunnel section and connected to the aircraft.
The tunnel section includes a plurality of tunnels which are telescopically fitted to each other. The tunnel section is extendable and retractable over the entire length in a front-rear direction (lengthwise or longitudinal direction). With this configuration, a change in a distance between the terminal building and the aircraft can be properly dealt with. In this case, floors of the tunnels form a walkway for the passengers between the platform of the terminal building and an entrance of the aircraft in the airport.
Adjacent tunnels with an outer-inner-tunnel relation are telescopically fitted to each other. In this structure, a stepped portion is formed in the walkway constituted by these tunnels. This impedes smooth walk of the passengers (travelers). Under the circumstances, a stepless structure of the walkway for eliminating the stepped portion has been proposed.
For example, Patent Literature 1 and Patent Literature 2 disclose a configuration in which the outer tunnel of the adjacent tunnels includes a movable walkway comprised of a plurality of floor members, and the movable walkway of the outer tunnel is moved to the underside of the floor of the inner tunnel. In the example disclosed in Patent Literature 1, the first end (one end) portion of the movable walkway is secured to a fixed walkway provided at the tip end portion of the outer tunnel. In the example disclosed in Patent Literature 2, the first end (one end) portion of the movable walkway is secured to a fixed walkway of a cab (head) provided at the tip end of the outer tunnel.